Produção Nacional
GEOCRONOLOGIA, ASSINATURA ISOTÓPICA E MODELO METALOGENÉTICO PARA O DEPÓSITO DE OURO CÓRREGO PAIOL, TOCANTINS, BRASIL
2016; Sociedade Brasileira de Geologia; Volume: 36; Linguagem: Inglês
ISSN
2177-4382
AutoresEmílio Lenine Carvalho Catunda Da Cruz, Raul Minas Kuyumjian,
Tópico(s)Geochemistry and Elemental Analysis
ResumoThe Almas-Dianopolis Terrane(ADT) composes most of the basement of the northern segment of the External Zone of the Brasilia Fold Belt and hosts several gold showing sand small deposits as well. The most important is the Iode orogenic-type Corrego Paiol Iode gold mine, hostedby hydrothermally altered high-Fe amphibolite and metagabbro. The deposit was formed by mineralizing fluid under greenschist facies conditions. Host amphibolite retained two argon reservoirs,related to the Transamazonian (-2.0 Ga) and Brasiliano(-700 to -535 Ma) orogenies. Geothermobarometric calculations and 40 Ar_ 39 Ar age spectra showed that mineralization (563± 15 Ma)took place during near isobaric cool ingstage that followed the isothermal decompression(started around -700 Ma) of the host terrane, which are part of a collisional clockwise P-T-t trajectory developed during the Brasiliano Orogeny. Whole rock and pyrite lead isotopes indicate that lower and upper crusts contributed with lead and gold to the Corrego Paiol deposito Stable isotopes in carbonate suggest a mixture of deep-seated carbon and oxygen, originated in the host terrane, and carbon and oxygen from Meso-Neoproterezoic metasedimentary cover. The isotopic, field and petrographic data gathered in this work, and compared with data from literature, allow for placing the Corrego Paiol gold mine as an element of a cratonic-scale metallogenetic event developed in the western margin of Sao Francisco Craton during Brasiliano Orogeny.
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